Apparatus for making conical tubular bodies



Sept. 15, 1936. I GRQSS 2,054,370

APPARATUS FOR MAKING CONICAL TUBULAR BODIES Filed Jan. 22, 1934 4Sheets-Sheet 1 Sept. 15, 1936.

F. GROSS 2,054,370

APPARATUS FOR MAKING CONICAL TUBULAR BODIES Filed Jan. 22, 1954 4Sheets-Sheet 2 Sept. 15,.1936. F. GROSS 2,054,370

APPARATUS FOR MAKING CONICAL TUBULAR BODIES Filed Jan. 22, 1934 4Sheets-Sheet 3 o h Q Q j 3 W i s} Q j m a J INVENTOE %u-1 L6TW F. GROSSSept. 15, 1936.

APPARATUS FOR MAKING CONICAL TUBULAR BODIES Filed Jan. 22, 1934 4Sheets-Sheet 4 fig. 12

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Patented Sept. 15, 1936 APPARATUS FOR- MAKING CONICAL TUBULAR BODIESFritz Gross, Dusseldorf, Germany Application January 22, 1934, SerialNo. 707,778

, In Germany January 24, 1933 Claims.

Application has been filed in Germany on the 24th January, 1933.

The invention relates to a method of and means for making conicaltubular bodies, for instance 5 posts and tubes, the main novel featureof which is the fact that the workpiece consisting of a cylindricaltubular body remains stationary and that the drawing tool is movedrelatively to the stationary workpiece. The drawing tool is mounted upona slide which is moved to and fro. The slide is associated with controlmeans which limit in a variable manner the commencement and the end ofthe stroke or travel of the slide and which also automatically controlthe forward and return movement of the slide. Further control means areprovided for bringing the drawing tool automatically into action atcertain variable times or portions of the travel. The conical tubularbody is made from a cylindrical workpiece in several operations, theaction being entirely automatic up to its completion. The number ofoperations depends upon the nature of the material and the requiredconicity. The drawings indicate by way of example the improved methodand a machine suitable for carrying out same.

Fig. 1 shows the initial blank consisting of a cylindrical body, fixedat one end in a-holder.

Fig. 2 shows the same workpiece after the first 80 working operation.

Fig. 3 shows the workpiece after the second operation. 4

Fig. 4 shows the completely drawn conical workpiece. 35 Fig. 5 shows atube having alternating cylindrical and conical portions drawn inaccordance with the invention by a slightly modified working method.

Fig. 6 is an elevation of the drawing tool. Fig. 7 is a section on line1--1 of Fig. 6. Fig. 8 is a front elevation of a machine for carryingout the improved method.

Fig. 9 is a rear elevation of the machine. Fig. 10 is a sectionalelevation of the machine 45 on line |0-|0 of Fig. 11. s Fig. 11 is a topView of the machine. Fig. 12 is a cross section on line |2-|2 of Fig. 8drawn to a larger scale.

The drawing tool or die consists of two rings or 50 rollers 3 and 4which are rotatably mounted in a movable slide so that they contact witheach other upon their peripheries. Each of the rollers is formed uponits periphery with a recess of semicircular cross section, the size orradius of 55 the semicircular cross section being a minimum at one pointand gradually increasing to a maximum, as may be seen from Figs. 6 and7; Upon the shafts 5, 9 of the rollers 3, [are mounted toothed gears 6,l0 engaging with each other so 60 that upon rotation of one roller theother roller is also positively rotated. The rollers are so mounted sideby side that at their point of contact the two recesses form an exactlycircular die opening. By turning the rollers-simultaneously the dieopening and the passage through 5 the rollers may be increased orreduced according to the direction of rotation. The maximum die openingor passage corresponds to the outer diameter of the cylindrical tubularworkpiece i from which the conical tubular body is to be made, whilstthe smallest die opening corresponds to the minimum diameter at the endof the finished conical tubular body.

The manufacture of the conical tubular body takes place in severalworking operations. In the example illustrated by Figs. 1 to 4, foursuch working operations.(A-D) are used.

The cylindrical tubular body I is firmly held at one end in a holder 2.The other end of the cylindrical workpiece is either unsupported, or 20inthe case of very large workpieces, it is supported by any suitablemeans. The slide which carries the drawing tool slides in a bed 1 of themachine frame 8. Before the commencement of the first working operation,the slide is in the position shown in Fig. 10. A pump ll forces pressurefluid through conduit l2 and a hollow stationary piston l3 into acylinder Hi. The drawing tool 3, 4 is opened so as to provide themaximum die opening. The slide which comprises the cylinders I4, newadvances until the drawing tool reaches the position indicated by theletter A in Fig. 1. In this position'a stop 15 carried by the slideencounters a first stop A upon a control drum IT. The control drum [1 isnow carried by the slide towards the end iii of the machine. Thismovement of the drum compresses a spring l8 supported at the other endby a stationary sleeve I! upon a control rod 20. Upon increase of thespring pressure a control lever 2| is turned and the spring l8 pushesthe rod 20 towards the head end of the machine. By this movement of thecontrol rod 20, control valves located at 22 in the frame are reversedand the pressure fluid is now admitted via conduit 23 and through thestationary hollow. piston 24 into the cylinder 25. Theslide now moves inthe direction towards the tail end 28 of the machine. During thismovement of the slide, the rollers 3, 4 constituting the drawing: toolare 1 slowly and uniformly rotated by means hereinafter described so asto reduce the opening of the die, whereby the workpiece is drawnconically from the point A to its end, this constituting the firstdrawing operation. The slide moves towards the tail end of the machineuntil the stop l5 encounters anannular stop 21 upon the drum H. The drumI1 is now moved towards the tail end of the machine compressing a spring28 against a stationary sleeve 29 of the control rod 20. By this means,the locking lever 2| is turned in the opposite direction, and the spring28 pushes the control rod 20 towards the tail end of the machine,whereby the control valves 22 are again reversed and pressure fluid isagain admitted into the return cylinder I4. The stop I5 on coming intocontact with the annular stop 21 of the drum I1 simultaneouslyencounters a stop ring 30 of a spring controlled movable rod 3|. Thiscauses by means of a ratchet gear ing stroke so as to produce a smallerdie opening, and the workpiece is simultaneously drawn to a conicalshape from the point B to its end (Fig. 3), thistorminating the seconddrawing operation. On being admitted to the cylinder 25, the pressurefluid is simultaneously admitted via conduit 33 to a control device 34and moves a control piston 35 towards the head end of the machine. Thismovement displaces a control rod 36 carried by swing arm 31, the rod 36being simultaneously moved towards the head end of the machine andtowards the centre of the machine. The rod 36 movesa coupling member 38.towards the centre of the machine and causes the claws of the couplingto engage those of a corresponding coupling member 39 fixed to a toothedwheel 40. The toothed wheel 40 is fixed upon a shaft 3 upon which isfixed the roller 4 of the drawing tool and a toothed wheel l0.

Duringthe drawing operation, the toothed wheel 40 rolls upon astationary toothed rack 42 and thereby causes rotation of the rollers 3,4 of the drawing tool. The diameter of the/toothed wheel 40 and thetoothed rack 42 are chosen in accordance with the required conicity ofthe conical tubular body to be produced. In the described example therollers 3, 4 turn during their movement from the point A to the end ofthe tube through about one-quarter of their peripheries. At the point Athe rollers 3, 4 provide the greatest die' opening and on arriving atthe end of the tube, the die opening has been correspondingly reduced bythe one-quarter rotation of the rollers. Owing to this rotation of therollers the portion of the tool from the point A to the end is conicallydrawn. For instance, the diameter of the workpiece may be, at the pointA 16 mm. and at the end) of the tube 14 mm. 3

During the second working. operation the rollers 3, 4 turn from B to theend of the tube from the point corresponding to maximum die openingthrough about one half of their peripheries. Consequently the workpieceis made conical from the point B, for instance, the diameter being 16mm. at B and 12 mm. atthe end. During the third working operation, therollers 3, 4 are turned through three-quarters of their peripheries fromthe point C, the tube being'therefore at C 16 mm. and at the end 10 mm.After the fourth drawing operation the tube is 16 mm. at D and 8 mm. atthe end. At the end of the last working operation, the ing tool are thenin the position shown in Fig. 7, corresponding to the minimum dieopening.

A watch spring 42 fixed to a stationary bolt 43 rollers of the draw istensioned by the rotation of the shaft 5. The

pressure fluid on being admitted into conduit l2 in the end position ofthe slide-at the tail end of the machine, is simultaneously admitted toa conduit 44, whereby piston 35 and rod 36 are pulled towards the tailend of the machine. The rod 36 is simultaneously moved outwards, thatis, away from the centre of the machine by the swing arms 31, and thecoupling member 38 is moved out of engagement with the coupling member39 of the toothed wheel 40. The tension spring 42 now comes into actionand turns the rollers 3, 4 of the drawing tools back into their initialposition corresponding to the maximum die opening. Consequently, therollers 3, 4 are always open to the'maximum die opening during anyreturn of the slide to the points A, B, C, D. It will be seen that thelength of the drawing stroke increases during the four draw-.

case in which the length of the tube, the re-' quired conicity of thetube, the recess of the rollers of the drawing tool and the proportionof the toothed wheel 40 to the toothed rack 42 are fixed relatively toeach other.

With the same drawing tools, shorter tubes having a greater conicity andlonger tubes having a smaller conicity may be produced. For this purposethe .toothed rack 42 is displaceably mounted and a further toothed rack45 is fixedly mounted 'upon the return cylinder I4. During the drawingoperation, the toothed rack 45 turns a toothed wheel 46 and thismovement istransmitted by gears 41, 48, 49, so as to move in accordancewith the selected rate of transmission, the toothed rack 42 in thedirection of the draw. Owing to the toothed rack 42 being moved in thedirection of the draw, the rotation of the rollers 3, 4 is retarded andconsequently the conicity of the tubular workpiece produced 'is re-'duced. By putting the gear 49 out of action, the toothed rack may, inaccordance with the selected rate of transmission of the intermediategear, be moved in a direction opposite to the direction of the draw. Bythis means, the rotation of the rollers '3, 4 may be accelerated and agreater conicity of the workpiece may be attained.

It is desirable that the rollers of the drawing tool should not actduring each drawing operation upon the same portion of the periphery ofthe workpiece, as owing to the existing gap in the die opening,longitudinal ribs might be produced upon the slide which at the end ofthe drawing operation strikes a stop 52 of a control rod 53. The controlrod 53 is, bythis means, drawn towards the tail end of the machine andthis movement is transmitted by a set of levers 54 to a toothed segment55, whereby a bevel gear 56 of a control device 51 are actuated toturn'the holder 2 and the workpiece, I.

-In order to stop the machine after the last drawing operation thefollowing device is provided. After the stop I 5-has encountered theannular stop 21 of the .control drum l1 and has moved the latter up tothe fixed annular stop 29 of the control rod 20 and has turned thecontrol rod I 1, the stop releases the locking device 2! and the groovesincreasing in cross section said toothed rack the pump I.

an exchangeable tensioned spring 28 has the tendency to reverse 4 Thisis prevented by a lever 58 which is fixedly mounted upon the control rod20 at the head end of the machine.

stop 59 which is mounted upon the bearing standard of the head end ofthe machine, so that the valve of the pump moves only half, of itsstroke and consequently assumes a position in which the pressure fluidcannot enter into the conduit used for the return movement of the slide.the slide carrying the drawing tool will remain in its initial position.If now the control drum' be turned by hand until the above mentionedlever 58 clears the fixed stops upon the ard, reversal of the pumpvalves will take place immediately by the still tensioned spring 28 andthe drawing operation will take place as above described. With the abovedescribed means, individual sections of a cylindrical workpiece may beconically drawn. ing tool remaining stationary, the workpiece may, ofcourse, be drawn cylindrically. In this manner tubes having alternatingcylindrical and conical sections, as shown in Fig. 5, may be produced.

Iclaim:

' 1. A drawing bench formaking conical tubular bodies from cylindricaltubular bodies comprising in combination: ,a stationary workpieceholder; a drawing tool adapted to be moved to and fro with regard 7 saiddrawing tool consisting of two rotatable rollers having upon theirperipheries grooves increasing in cross section from one end totheother; means-for rotating said rollers of the drawing tool during thedrawing operation; and means for varying the rotation of the rollersduring the working stroke, said means for rotating to a variable extentsaid rollers of the drawing tool comprising. a toothed wheel movingsimultaneously to and fro with the tool and operatively connected withthe rollers'of the drawing tool; a toothed rack co-operatmg with saidtoothed wheel; and means\for imparting a movement to the toothed rack inthe forward and backward direction for the purpose of retarding oraccelerating the rotation of the toothed wheel actuating the rollers ofthe drawing tool, substantially as described.

2. A drawing bench for making conical tubular bodies from cylindricaltubular bodies, comprising in combination: a static holder; a drawingtool adapted to be moved to and fro with regard to said holder over theworkpiece, said drawing consisting of two rotatable rollers having upontheir peripheries to the other; means for rotating said rollers of thedrawing tool during the drawing operation; and means for varying therotation of the rollers during the drawing stroke, said means forrotating to a variable extent said rollers 01- the drawing toolcomprising; a toothed wheel moving simultaneously to and fro with thetool and operatively connected with the rollers of the drawing tool; atoothed rack co-operating with said toothed wheel; and means forimparting a the toothed rack in the forward purpose of retarding oraccelerating the. rotation of the toothed wheel actuating the rollers ofthe drawing 'tool, said last mentioned means for moving in the one orthe other vdirection comprising a second toothed rack connected controlrod at the Consequently,

bearing stand- With the rollers of the drawto said holder over theworkpiece, movementl'means for increasing after each nary workpiece fromone end with the drawing tool so as stationary toothed rack with thedrawing tool and reciprocating therewith and an intermediate changeabletransmission gear interposed between the two toothed racks,substantially as described.

3. A drawing bench for making conical tubular bodies from cylindricaltubular bodies, comprising in combination: a stationary workpieceholder; a reciprocable drawing tool comprising two rollers havingperipheral grooves of a section increasing from one end to the other;hydraulic means for moving said drawingtool relatively to the workpiece;and means for automatically increasing the strokeof the drawing toolduring subsequent operations, saidmeans comprising: a rotatable drum;means for rotating said drum after each drawing number of stops uponsaid drum; means for reversing the movement of the drawing tool operatedby said stops, substantially as described.

4. A drawing bench for making conical tubular bodies from cylindricaltubular bodies, comprising in combination: a stationary workpieceholder; a drawing tool consisting of two rollers curved upon theirperipheries, the sections of the curves increasing gradually in onedirection;

' means for repeatedly moving the drawing tool forwards and backwardsrelatively to the workpiece; means for increasing after each forward andbackward movement of the drawing tool relatively to the workpiece thelength of said for rotating the two rollers of the drawing tool duringeach drawing operation by a variable amount increasing after each oper-1 ation, said means for moving the drawing tool relatively to thestationary workpiece comprising .a hydraulic cylinder and-valve meansfor controlling the supply of pressure fluid to said cylinder, saidvalve means being operable by the movement of the drawing tool; andspring means for returning the rollers to the position corresponding tothe maximum die opening at the end ,of each drawing opera '0 5. Adrawing bench for making conical tubular bodies from cylindrical tubularbodies, comprising in combination: a stationary workpiece holder; adrawing tool consisting of two rollers curved upon their peripheries,the sections of the curves increasing gradually in one direction; meansfor repeatedly moving the drawing tool forwards and backwards relativelyto the workpiece; means forward and backward movement of the drawingtool relatively to the workpiece the length of said movement; means forrotating the two rollers of the drawing tpol during each drawingoperation by a variable amount increasing after each operation, saidmeans for moving the drawing tool relatively to the stationary workpiececomprising a hydraulic cylinder and valve means for controlling thesupply of pressure fluid to said cylinder, said valve means beingoperable by the movement of the drawing .tool; and spring means forreturning the rollers to the position corresponding to the maximum dieopening at the end of each drawing operation, said means for rotatingthe rollers comprising a toothed wheel connected to participate in themovement of the drawing tool; a operating the said toothed wheel; andmeans for transmitting the movement of the toothed wheel to the rollersof the, drawing tool,

longitudinal FRITZ GROSS.

operation; a

substantially as described.

